Errors in baking normals. I'm either doing something super dumb or I'm not using normals the way they're supposed to be used. Please help
The baking works fine, the problem is that all your details are completely parallel or perpendicular to the low poly faces normals. Baking the normals will only be able to scan the faces normals that are not parallel or perpendicular to the rays, bake normals save the faces normals direction, not the faces height.
Here, no bake possible:

Here, the oblique faces are not perpendicular or parallel to the ray so they will be baked:

If your high-poly ever go through the surface of your low-poly, tweak the Ray Distance value so that it nows begin a bit before the low-poly surface (you may also need to tweak the Extrusion value):

In your case, if I scale down one of your details and bake, as the normals are now oblique it will be saved on the normal map, the other ones won't: